Dry Skin in Winter Is Caused by Your Shrinking Skin Cells, Says Study

Winter dry skin is an annual beauty given. As soon as the season changes, your skin does, too, suddenly developing an unquenchable thirst. A new study helps explain exactly why it is that your skin texture changes with the seasons.

The onslaught of cold winter air can be a disaster for your skin — battling constant dryness is not an uncommon problem for patients, Sejal Shah, a board-certified dermatologist in New York City, tells Allure. The worst part? It often comes with added sensitivity and irritation and, in some cases, severe skin issues like eczema and psoriasis flare-ups.

In a study published this month in the British Journal of Dermatology, researchers looked at what’s happening at the cellular level to make it feel like you suddenly have totally different skin from season to season.

It turns out, it largely comes down to a protein, called filaggrin, says Jacob Thyssen, a professor of dermatology at the University of Copenhagen and a co-author on the study. Filaggrin is an important skin protein that plays an “architectural role” in your skin barrier. “After this function, filaggrin is degraded to amino acids that maintain hydration within the cells and provide protection against solar UVB photons,” he says. The process is essential for making sure your skin keeps producing it’s natural moisturizing factor (NMF), adds Shah.

When examined at high magnification, researchers found that cold, dry air can make your the outermost layer of skin cells to essentially shrink and encourage your filaggrin stores to degrade, which leads to that dry, scaly texture. You’re most likely to experience the texture change on your cheeks and hands, says Thyssen, since that area of your skin is naturally lower in filaggrin. “An additional reduction of filaggrin at these sites will cause dry skin and increase the risk of inflammation,” he explains.

Whether you have a history of eczema or simply dry skin, it’s important to adjust your skin-care routine with the changing of the seasons. “As temperatures start to fall, switch to more hydrating skin care products,” says Shah. “Regularly exfoliate — but don’t overdo it — cover exposed areas when going outdoors, and use a humidifier.”